Synthesis and structure of new bicopper(II) complexes bridged by N-(2-aminopropyl)-N′-(2-oxidophenyl)oxamide: The effects of terminal ligands on structures, anticancer activities and DNA-binding properties

A novel dissymmetrical N,N'-bis(substituted)oxamide ligand, N-(2-aminopropyl)-N'-(2-oxido- phenyl) oxamide (H(3)apopoxd) (L), and its three bicopper(II) complexes, [Cu-2(apopoxd)(bpy)]- (ClO4)center dot H2O (1), [Cu-2(apopoxd)(dabt)](ClO4)center dot 2H(2)O (2), and [Cu-2(apopoxd)(phen)(2)](ClO4) (3) (bpy = 2,2'-bipyridine; dabt = 2,2'-diamino-4,4'-bithiazole; phen = 1,10-phenanthroline) have been synthesized and characterized. The crystal structures of the three bicopper(II) complexes have been determined by X-ray single-crystal diffraction. In complexes 1 and 2, the cis-apopoxd(3-) ligands bridge two copper(II) ions in square-planar geometries with the corresponding separations of 5.1868(3) and 5.2016(4) angstrom, respectively. While in complex 3, the apopoxd(3-) ligand adopting a trans conformation bridges the two copper(II) ions in distorted square-pyramid environments with a Cu center dot center dot center dot Cu distance of 5.2508(7) angstrom. The anticancer activities and DNA-binding properties of L and the three complexes were investigated. (C) 2011 Elsevier Masson SAS. All rights reserved.